Bullock's last film, 2009's "The Blind Side," was the kind of career apogee of which most actresses dream, winning her a best actress Academy Award in what essentially amounted to a coronation of Bullock as America's most beloved female movie star.

But the accomplishment — which would normally be followed by a wave of projects to capitalize on the momentum — was soon marred by public scandal. Bullock's husband, "Monster Garage" host Jesse James, was revealed to have been unfaithful. The fallout, which led to divorce, was covered relentlessly by the tabloids. Bullock still went ahead and adopted a baby boy.

When Daldry, the director of "The Hours" and "The Reader," approached her about "Extremely Loud," Bullock wasn't sure she would return to acting at all.

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"I was perfectly content to be permanently broken," she says. Recognizing how that might sound in print, she smiles at the unintended hint of her personal turmoil, and adds "time-wise" to clarify the break as one from moviemaking.

"I honestly didn't think I was in a place where I wanted to work or wanted to step out of where I was," she says. "I wasn't prepared. But the opportunity was louder than my head."

The chance was to play a supporting but key role in Daldry's adaptation of Jonathan Safran Foer's novel. In it, Bullock plays the mother of an uncommonly bright, precocious child (Thomas Horn), whose father (Tom Hanks) dies on Sept. 11. It's a particularly wrenching story about grief and reconciliation.

"I needed a partner in the project, somebody that would be a leading lady and look after me, look after herself, look after the character, look after the kid and look after the creation of the whole process," says Daldry. "Sandy was literally like a partner on it for me. We would write and rewrite and focus down."

One of the film's most striking and emotional scenes is a flashback to Bullock's character speaking on the phone with her husband, who is calling from atop one of the burning towers.

"The thing that made it so poignant for me was that Tom Hanks showed up that day," says Bullock. "He sat in a room not far from where I was and made that call every single time. Every time I pick up that phone, it was Tom Hanks on the other end of the line. My husband who is calling because he knows he's going to die, giving me some gift, some joy, some jewel — something that he can leave me with so he knows I'm going to be OK."